Sample preparation plays an important role in the DNA analysis workflow. Real samples often include a complex matrix, such as blood and other bodily fluids, or exogenous impurities, e.g., from the scene of crime. Most of the common nucleic acids isolation techniques are based on extractions; however, isotachophoretic focusing has recently attracted some interest for its simplicity and potential for very high enrichment factors and ease of automation. Here, we report on the use of a commercial isotachophoretic instrument for optimization of DNA focusing and preparative fraction collection. In order to achieve a high recovery and enrichment, experimental factors including electric current, sample amount and matrix were investigated experimentally as well as by computer simulation. The sample of a DNA ladder was injected in 30 μl volume and after ITP focusing the DNA zone was recovered using an on-column micropreparative collection valve. The DNA content in the collected sample was verified by fluorescence spectrometry and chip capillary electrophoresis with fluorescence detection.

样品制备在DNA分析工作流程中起着重要作用。真实样本通常包含复杂的矩阵，例如血液和其他体液，或来自犯罪现场的外源杂质。大多数常见的核酸分离技术都是基于提取的。然而，等速电泳聚焦最近因其简单性和潜在的非常高的富集因子以及易于自动化而引起了人们的兴趣。在这里，我们报告了使用商业等速电泳仪器优化DNA聚焦和制备级分的收集。为了获得较高的回收率和富集率，对实验因素包括电流，样品量和基质进行了实验研究，并通过计算机模拟进行了研究。注入30μl体积的DNA阶梯样品，ITP聚焦后，使用柱上微量制备收集阀回收DNA区域。收集的样品中的DNA含量通过荧光光谱法和带荧光检测的芯片毛细管电泳进行验证。